Simplified Noise Evaluation of Microwave Receivers

The noise figure for arbitrary source admittance can be computed from the noise figure at any one source admittance and the output noise when passive one-ports are connected to the receiver input, if input admittance is known. The procedure is demonstrated experimentally at 4000 MHz with offset short circuits as the passive one-ports. The input admittance determined by mismatched noise sources agrees with network analyzer measurements.